Focal therapy for localized prostate cancer: a treatment “in puberty”

In the past decade we have moved from some early investigations into the potential of focal therapy as a treatment for localized prostate cancer to the early implementation of such processes (of varied types). The actual effectiveness and safety of such forms of therapy are still, however, awaiting proof through long-term follow-up data.

What do we mean by “focal therapy”? Focal therapy for localized prostate cancer is analogous to the idea of “lumpectomy” as a treatment for localized breast cancer — the idea that it might be possible to treat the localized disease effectively by elimination of the specific focus of cancer in the prostate without the need to treat or remove the entire prostate gland. But there are two reasons why focal therapy for prostate cancer is, in real terms, a lot more difficult than lumpectomy for breast cancer:

  • The prostate cancer is located in a place that makes it very difficult to be sure you have accurately identified the small local lesion that needs to be removed or killed.
  • Prostate cancer is a “multi-focal” disease, which means that all too often the primary focal lesion isn’t the only lesion (raising the question of whether focal therapy is really possible in a particular patient).

Then there is the question of which patients are appropriate candidates for focal therapy. This is also hard to make declarative statements about, but here are two general groups of potential candidates:

  • Men with a small, well-defined amount of low- or very low-risk disease who are unwilling to consider active surveillance as a first-line management strategy
  • Men with a small, well-defined amount of intermediate-risk disease

What do we mean by “a small, well-defined amount of” very low-, low-, or intermediate-risk disease? Good question. It’s a bit of a moving target. The actual criteria for who is a good candidate for focal therapy is a work in progress, but most experienced investigators would seem to agree that sophisticated imaging tests and biopsying techniques should be applied before one can tell an individual patient that he is or is not a good candidate.

How can focal therapy be carried out?

Actually, we have several mechanisms that – at least in theory – can be used effectively to conduct focal therapy. They include:

  • Focal cryosurgery
  • Focal laser ablation (FLA)
  • Focal forms of high-intensity focused ultrasound (HIFU)
  • Focal forms of external beam radiation therapy — potentially including focal forms of stereotatic body radiation therapy or SBRT (e.g., CyberKnife radiation)
  • Focal forms of irreversible electroporation (IRE) using a NanoKnife device
  • Focal forms of radioactive seed implantation (i.e., focal brachytherapy)
  • Focal forms of photodynamic therapy

However, despite all these hypothetical (and actual) opportunities, what we do not have as yet are:

  • Published data from even one significant series of well-characterized patients treated by a single type of focal therapy and followed, post-treatment, for an average of even 2 years
  • Complete agreement among the focal therapy research community about who are the most appropriate candidates for which types of focal therapy

What we do have, on the other hand, is increasing consensus among opinion-leaders in the focal therapy treatment community about priorities in the conduct of focal therapy.

All that The “New” Prostate Cancer InfoLink really feels able to tell patients at this time is that focal therapy does represent an opportunity – most particularly for those patients with low-volume, intermediate-risk prostate cancer. The “New” Prostate Cancer InfoLink absolutely does not wish to discourage any man interested in the potential of focal therapy from considering, evaluating, or actually having such therapy. Indeed, we actually encourage some men to consider this as a treatment option (if they can get their health plan to pay for it, or if they can afford to pay for it themselves). On the other hand, we do wish to be very clear that all such men need to evaluate opportunities for focal therapy “with eyes wide open” as to the possible downsides as well as the potential upsides.

Content on this page last reviewed and updated December 3, 2014.
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